A gas turbine engine generally includes, in serial flow order, a compressor section, a combustion section, a turbine section and an exhaust section. In operation, air enters an inlet of the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section through a hot gas path defined within the turbine section and then exhausted from the turbine section via the exhaust section.
In particular configurations, the turbine section includes, in serial flow order, a high pressure (HP) turbine and a low pressure (LP) turbine. The HP turbine and the LP turbine each include various rotatable turbine components such as turbine rotor blades, rotor disks and retainers, and various stationary turbine components such as stator vanes or nozzles, turbine shrouds and engine frames. The rotatable and the stationary turbine components at least partially define the hot gas path through the turbine section. As the combustion gases flow through the hot gas path, thermal energy is transferred from the combustion gases to the rotatable turbine components and the stationary turbine components.
In general, the HP turbine and LP turbine may additionally include shroud assemblies which further define the hot gas path. A clearance gap may be defined between the shroud of a shroud assembly and the rotatable turbine components of an associated stage of rotatable turbine components. The shroud is typically retained within the gas turbine engine by a shroud hanger, which in turn is coupled to various other components of the engine.
One issue with presently known shroud assemblies (and in particular ceramic matrix composite shroud assemblies) is the structural rigidity of the shrouds as they experience relative substantial loading during operation of the engine. Recently developed shrouds, for example, have utilized an “open” style wherein flanges at the forward and rear ends of a shroud body extend from the shroud body for coupling the shroud to the hanger. Distal ends of the flanges are free ends, not coupled to other components (such as cross-beams) of the shroud. While such open style designs provide numerous advantages with respect to manufacturability, concerns have arisen with respect to the structural rigidity of these shrouds. For example, pressure differentials during operation of the engine cause relatively substantial loading on the shrouds. Further, such loading can be uneven on the surface of the shroud. These loads can cause stresses the intersections of the flanges and shroud body, which can lead to shroud damage. Such issues are of increased concern when the shrouds are formed from ceramic matrix composite materials.
Accordingly, improved shrouds and shroud assemblies for gas turbine engines are desired. In particular, open style shrouds with improved structural rigidity are desired.